Compared with light intensity of less than 2500 lux, a light intensity of 2500 lux or greater had a greater effect on depression.

HealthDay News — For cognitively impaired individuals, light therapy has a moderate effect on behavioral disturbances (BDs) and depression, and a small effect on sleep quality, according to a meta-analysis published in the Journal of the American Geriatrics Society.

Huei-Ling Chiu, RN, from Taipei Medical University in Taiwan, and colleagues conducted the analysis of 9 randomized controlled trials to assess the effects of light therapy on BDs, sleep quality, and depression among cognitively impaired persons.

The researchers found that light therapy had a moderate effect on BD and depression and a small effect on total nighttime sleep (g = −0.61, −0.58, and 0.25, respectively).

Compared with light intensity of less than 2500 lux, a light intensity of 2500 lux or greater had a greater effect on depression. Studies deemed to be at low risk of bias regarding blinding had a greater effect size in terms of BD than those deemed to be at high or unclear risk of bias.